Fuel tank



Nov. 27, 1951 W. E. ATWOOD ET AL FUEL TANK Filed Sept. 29, 1949 I 6in1- l J9 14 E1. 3359 Jl 24 W je AZ4@ 4J J7 Z 2.5 j 4 37 JZ 10/ o Z2 20 lhwentors Gttorneg Patented Nov. 274, i951 Atwnna, Glendale; ana Rnbeu.: Holland, Sunland, Calif.

Application September 29, 14$llSer-i;al No. 7118361378' 7 claims. (C1. ies-46) r This inventionrelates to fuel tanks particularly for engine-powered model aircraft.

,Engineepowered model airplanes, particularly in competition with other airplanes, are restricted to, al certain maximum time of engine operation when started in flight. This time-restriction is particularly required when determining free iiightduration. Thus, all model airplanes of one class are own under similar conditions to determine the aero-dynamic superiority of one or more of said airplanesv over the others. However, each contestant desires to have his airplane under power for the full time period al lowed to thereby achieve maximum speed and/ r elevation before the engine ceases operation, all toward the end of achieving maximum free flight. As an example, if twenty seconds of engine operation are permitted, a contestant desires that the engine operate for the full twenty seconds and not for nineteen or nineteenand one-half, since the additional one or one-halfsecond may result in several more secondsl of sustained free Iiight. Also, operation of the engine for longer than the time allowed would result in disqualication.

It will be seen, therefore, thatA an extremely accurate amount of fuel must be fed to the engine to insure powered flight for a determined period of time. Many attempts have been made to achieve the accuracy desired but have fallen short for several reasons, the major of which is unduly great weight, a factor fatal to maximum and sustained free flight.

Recognizing the faults in prior fuel tanks for model airplanes, it is an object of the present invention to provide a novel and improved tank that is not only eflicient for the purpose intended, but is light in weight, being lighter, by twothirds, than some prior devices.

, Since a warm-up period for the engine is highly desired, fuel tanks necessarily must have a capacity considerably in excess of that amount of fuelwhieh is required for maximum powered flight of a model, airplane, so that said excess may be employed for warm-up. However, riot-all of 'such excess fuel is used up and assurancemust be had that the remainder thereof will not be conducted to the engine.

Another object of the invention, therefore, is to provide a fueltank that has a relatively large fuel capacity and in which a predetermiified.per-y tion of vthe Yfuel is separated, from the total ernennt in the tank. 'wneieynniysaia niederen nn' ed 'rtio'n isl dapted @pass inte' anfengin'e supplied by Said ta A; further obje'qt nf the invention is tp p rp ea fuel tank, as above, that, While supplying fu'eli for engine Warmup, can be opened instantly td effect separationof a predetermined portion of' the fuel inthe tank, whereby the vengine remains in continuous operation throughh the warm-up. period and the timed period` under pWl Y Y v This invention also has for its objects to pro- '1 nsuen meanstnat are' pqsiuye in aneignen,

Qnnynijnt in `use, easuyinstaued in a lWorking pe'sitionand easily disconnected therefrom, eco nomical of manufacture, relativelys imple,l and o f general superiority and serviceability. Y v Ihe invention also comprises nevel details of construction end novel combinations and arrangements of partis, which willmore fully appear in the course of the following description; lowever, the drawingsmerely show and thefollewing description merelydeseribes embodiments ofthe presentinventiom which -are given by Way of `illustration or example only. lnthe drawings, like referencevcharacters des,- ignate similar `parts in the several views.- Y .lig. 1 is apartially broken front vieWa seal+ ing cover plate being' removed, of onefform of fueltank according tothe present invention. vlfig. 2 is a cross-sectional view as taken .on line 2 2 of Fig. 1. A

liig. S-isan end View of another form of fuel tana Fig. 4 is a cross-sectional view as taken on line-4 4 of Fig. 3.'

Eig. 5 vis a partially broken front Viewv of .a mediiication based on the tankshown in Figs. 1 and 2.

With more particular reference to-ligs; l and g, thefuel tank comprises a body I0 that is preferably cast of a light metal. Saidbodyis formed tQ;- have afrusto-conical peripheral wall Il, a beek wall I2 closing the smaller side of the body, andfafront flange I3: In the plane of said flange and; somewhatdeeper than the thickness thereof, there is providedla concentric seat I4 that, ter'- minates at a fiat shoulder I5; Centrally of the bo dy, and across the interior thereof, there is provided a rib I8 extending from Wall I2.ina direction toward but short of shoulder I5. A tapped boss I'I is formed in the middle of said said, boss being located on the axial center of-.ihe may.

According to the invention; the interior of the body is divided by a partition I8, in to a-1arger upper; fuelchamben [Q and. a smaller lower fuel chamber 20. Said partition I8 extends from Wall Ii and termnates'at the plane of shoulder I5. The upper chamber I9 may vary in size and capacity, whereas the lower chamber 20 is of a size to hold a predetermined quantity of fuel.

An -outlet is provided for the tank, the same comprising a tube 2| set in a boss 22, residing in the lowermost portion of chamber 2D, and extending rearwardly from a front face 23 of boss 22 and outward of the body. Said face 23 is rearwardly spaced from shoulder I so that said tube 2| is in communication with chamber 20.

Suitable holes 24 in ange I3 are provided for mounting the tank to an airplane and suitable tapped holes 25, on the opposite side of the body, are provided for effecting connection of the tank to an engine supplied thereby.

The above-described body is provided with a sealing cover that comprises a gasket plate 26 fitting seat I4 and pressedtightly against shoulder I5 and front edge 21 of partition I8 by a screw orrbolt 23 threadedly engaged in tapped boss I1. A metal plate 29, superposed on gasket plate 26, is engaged by the head 33 of bolt 28 to effect'rm seating of the latter plate. Thus, chambers I9 and 23 are definitely' separated against flow from one to the other except as hereinafter described.

According to the invention, the tank I IJ is provided with means 3| which is primarily a valve and also comprises a ller tube for the tank and a breather for lower chamber 20. The means 3| comprises a tube 32 which, at one side of boss I1, extends through tank wall II and rib I6 to be held thereby in vertical alignment, said tube being slidably mounted for movement in the spaced bearings thus provided. The lower end 33 of said tube is conically formed and a preferably conical passage seat 34 is provided in partition I8 for said end as in Fig. 1. An expansion spring 35, coiled about tube 32, has one end in abutment with the inner face of wall I I or, as shown, with a loose collar 36 strung on the tube, and the other end confined in an annular groove 31 formed in said tube. Said spring, thereby, urges tube 32 in a direction to engage conical end 33 withvseat 34 and thus seat against ow from chamber I9 to chamber 20.

Tube 32 is adapted to be retained in elevated retracted position by a spring detent 38 mounted on the outer side of wall II, and an annular groove 39 in said tube receptive of said detent when the tube is pulled against the force of spring 35.

While the sliding fit of tube 32 in wall II may usually afford a suitable vent for chamber I9, if

desired, a separate vent 4|! in the uppermost portion of said wall may be provided.

In operation:

Tube 32 is pulled to engage detent 38 in groove 39 and, thereby, unseat tube end 33. The tank is now filled through passage 4| in said tube, the fuel'lling chamber 23 through seat 34 and then filling chamber` I9, either full or to any desired level as indicated by line 42. The engine is now started and adjusted in the usual manner, the fuel being drawn, through outlet 2 I, from chamber 29 which is maintained full, however, by being replenished from chamber I9 through open seat 34. Thus, only the level 42 lowers in chamber I9.

When the airplane is ready for launching, arm 43 of detent 38 is flipped in a direction to release tube 32 and allow spring 35 to project said tube, engaging end 33 in seat 34. i Chamber I9 V i,sfenow isolated from chamber and only the fuel in the latter may pass through outlet 2| td the engine. Consequently, said engine will operate for a period according to the amount of fuel in chamber 20 and will cease to operate upon depletion of said fuel. During the latter condition of the means 3|, passage 4I of tube 32 serves as a breather or vent for chamber 2li.

While chamber 20 maybe made exactly to the size desired, in practice, the same is made somewhat larger and one or more ller pieces 44 placed therein to reduce the fuel capacity to the exact size desired. Such ller pieces are employed to compensate for variation in full eciency, and once the sizes of such pieces are determined, they may be substituted accordingly.

The tank shown in Figs. 3 and 4 has a body 45 formed with a tubular part 4S, in which is formed an internal shoulder 41, and a conical extension 48 that terminates in an outlet 49. A partitioning plate 50 divides said body into upper and lower fuel chambers 5I and 52, respectively, said plate being held against shoulder 41 by a flange 53 on a cap 54 threadedly connected to the body. Plate 50 is the counterpart of partition I8 of the earlier-described tank and the means 3| is operatively associated therewith in the manner described for the earlier form. EX- cept for the smaller size, the tank of Figs. 3 and 4 is, in other respects, similar to that of the tank in Figs. 1 and 2, and will function in a comparable manner.

The modification of Fig. 5, which is shown as applied to the larger tank,l may also be applied, in asimilar manner, to the smaller tank. Said modification comprises a metering valve 551by means of which a Vsmall metered portion of fuel in chamber I9 isY added to the fuel supplied to the engine from chamber 29. This added fuel is supplied at a much lower rate than the rate at which the fuel in chamber 20 is diminished by the engine. Consequently, the engine will cease operation while the last few drops are yet entering chamber 2U from chamber I9.

Said valve 55 is preferably positioned parallel to tube 32 but on the opposite side of boss I1, and comprises a needle-pointed stem 56 that extends through a conical passage seat 51 in partition I8. Said stem is adjustable relative to said seat by a threaded part 58, and adjustment is retained as by a lock nut 59. Of course, by setting said stern down on its seat, metering is obviated.

While the invention that has been illustrated and described is now regarded as the preferred embodiments, the constructions are, of course, subject to modifications without departing from the spirit and scope of the invention. Itis, therefore, not desired to restrict the invention to the particular forms of Yconstruction illustrated and described, but to cover al1 modifications that may fall within the scope of the appended claims.

Having thus described the invention, what is claimed and desired to be secured by Letters Patent is;

1. A fuel tank of the character described, comprising a hollow body having a, partition therein dividing the same into two fuel chambers one above the other, there being a passage in said partition communicating the chambers, a slidably-mounted elongated member having a longitudinal passage and extending through the upper chamber, resilient means engaged with the bpdy'and said elongated member to project one end of the latter into said first passage to close flow lbetween the chambers and to vent the lower chamber through said longitudinal passage. de-

tent means normally releasably engaged with the elongated member to hold the same retracted and the chambers in communication, and an outlet for the fuel in thelower chamber.

2. A fuel tank of the character described, comprising a hollow body having a partition therein dividing the same into two fuel chambers, one above the other and the upper chamber being larger in capacity than the lower chamber, there being a passage in said partition communicating the chambers, a slidably mounted elongated member having a longitudinal passage and extending through the upper chamber, resilient means engaged with the body and said elongated member to project one end of the latter into said first passage to clos-e flow between the chambers and to vent the lower chamber through said longitudinal passage, detent means normally releasably engaged with the elongated member to hold the same retracted and the chambers in communication, and an outlet in the lower chamber for fuel therein. i

3. A fuel tank according to claim 1, embodying a metering valve controlling flow from one chamber to the other while the elongated member is projected to close flow between the chambers.

4. A fuel tank of the character described, comprising a hollow open-sided body, an apertured partition dividing the interior of said body into upper and lower fuel chambers, a closure for the open side of the body and sealed thereagainst to close flow of fuel between the chambers except through the aperture in the partition, a slidablymounted elongated member having a longitudinal passage and aligned with said aperture and extending through the upper of said chambers and guided in said body, resilient means to project said elongated member into said aperture to close flow between the chambers and to vent the lower chamber through said longitudinal passage, a releasable detent normally engaged with said elongated member outside of said body to hold the same retracted and effect communication of the chambers through the aperture, and an outlet in the lower chamber for fuel therein.

5. A fuel tank of the character described, comprising a hollow open-sided body, an apertured partition dividing the interior of said body into upper and lower fuel chambers, -a closure for the open side of the body and sealed thereagainst to close flow of fuel between the chambers except through the aperture in the partition, means to removably hold said closure in sealing position comprising a bolt extending through the closure from the outside and having threaded engagement with the body, a slidably-mounted elongated member having a longitudinal passage and aligned with said aperture and extending through the upper of said chambers and guided in said body, resilient means to project said elongated member into said aperture to close flow between the chambers and to vent the lower chamber through said longitudinal passage, a releasable detent normally engaged with said elongated member outside of said body to hold the same retracted and effect communication of the chambers through the aperture, and an outlet in the lower chamber for fuel therein.

6. A fuel tank of the character described, comprising a hollow open-sided body, an apertured partition dividing the interior of said body into upper and lower fuel chambers, a closure for the open side of the body and sealed thereagainst to close flow of fuel between the chambers extent through the aperture'in the partition, a slidablymounted elongated member having a longitudinal passage and aligned with said aperture and extending through the upper of said chambers, a rib in the interior of the latter chamber, said rib and a wall of saidbody having holes in alignment with the aperture in the' partition and constituting spaced slide bearings for the tubular member, resilient means to project said elongated member into said aperture to close flow between the chambers and to vent the lower chamber through said longitudinal passage, a releasable detent normally engaged with said elongated member outside of said body to hold the same retracted and effect communication of the chambers through the aperture, and an outlet in the lower chamber for fuel therein.

7. A fuel tank of the character described. comprising a hollow open-topped body having an internal shoulder facing the open end of the body, an apertured partition plate residing against said shoulder and dividing the interior of the body into upper and lower fuel chambers, a closure for the open top of the body and having a downreaching flange extension engaged with said plate to hold the same against displacement on said shoulder, an elongated member having a longitudinal passage and extending through said closure, through the upper clramber, and in axial alignment with the aperture in the partition plate, a detent mounted on the outside of the closure and releasably engaged with the elongated member to hold the same retracted from the aperture and thereby open the latter to communicate the chambers, and resilient means, operable upon release of the detent, to project the elongated member to close the aperture and stop flow between the chambers, and an outlet for the lower chamber.

WILLIAM E. ATWOOD. ROBERT L. HOLLAND.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 524,900 James Aug. 21, 1894 640,081 Bem'an et al. Dec. 26, 1899 1,116,778 Wilson Nov. 10, 1914 1,25,797 McDade et al Mar. 1 2, 1918 1,990,604 Johnson Feb. 1 2, 1935 1,990,605 Johnson Feb. 12, 1935 

